It's unlikely that you'll ever get much facial detail in a long shot on DV: you only have 720 pixels across a frame, and if you're a long way away there simply aren't enough pixels to give much detail.

Also, DV camera lenses tend to be sharpest in the middle of the aperture range, so if it's wide open or shut down you'll lose more detail.

so if i use HDCAM for long shot will the charectors face detail will be clear ? or else which camera is can give me best result?

Yeah, HDCAM will give you about four times as many pixels as DV (even more with HDCAM-SR, I believe).